Defective chip on ribbon cables

[Lloyd6202]

Need to know if there is damage to this ribbon cable. Ive never seen what a damged on looks like and if these ribbons are repairable.

[dick_barton]

Re: Defective chip on ribbon cables

It does look as though the chip has been cooked. If it has been then there's no cost effective repair.

[Lloyd6202]

Re: Defective chip on ribbon cables

Sounds good soo what is the first thing i need to do there is a couple of the ribbons that look like this! How do i test them and what would cause this

[dick_barton]

Re: Defective chip on ribbon cables

If it is cooked then I don't think there is anything you can do to save the panel. From the picture it's hard to tell what has happened to them. It could be caused by water ingress if the screen has been wiped down with a too damp a cloth and this tends to affect the circuit boards located at the bottom of the set. If this is a plasma set and these are the boards at the bottom of the set then the chips (COF) can fry if the heatsink is not fitted in place when the set is run.
Do you have a photo of the complete back of the set showing where this board is.
What's the tv model number?

[Lloyd6202]

Re: Defective chip on ribbon cables

So the horizontal lines in the top half are from damaged ribbon chips?? And when tv starts up im left with a square of stic that alternates throug the top hal bouncing back and forth. Im waiting for. Ysus buffer board that will be here monday. How do i test the ribbons to see if anymore are damaged and how do i replace them

[Lloyd6202]

Re: Defective chip on ribbon cables

Ive replaced half of the parts. Ysus and Zsus Along with powersupply..

[dick_barton]

Re: Defective chip on ribbon cables

I thought I've seen these pictures before. You have two threads running regarding the same fault which people will find confusing.
It's best to close one down and redirect.

[dick_barton]

Re: Defective chip on ribbon cables

What circuit board is shown in post #1. Is it the long circuit board running across the bottom?

[Lloyd6202]

Re: Defective chip on ribbon cables

Yes XYZ buffer boards under the heat sink

[Lloyd6202]

Re: Defective chip on ribbon cables

And i dont know how to delete other thread so i posted link to this one

[Lloyd6202]

Re: Defective chip on ribbon cables

Well im crashin worked nightshift last night hope to get some good feedback on this as im not ready to throw the towel in yet...

[dick_barton]

Re: Defective chip on ribbon cables

Then I suspect they may be OK (the white uneven look on the COF chip in post #1 could be heatsink compound) since photo 2 shows a full width image even if it is static. If one of those COF chips were damaged you would have a blank bar running top to bottom as in photo #3.

Don't run the set without the heatsink back in place or you will damage the IC's on the ribbons and the set will be scrap.

The lower Y buffer section appears not to be working (half picture missing) so although you said you have replaced it I would check it for short circuit buffers. There are plenty of Youtube video's showing you how to check them for short circuit.

The reddish picture could be a problem with the Xsus board. I note that when the coils on the X board are not well soldered it tends to give a pinkish picture.

Have you measured and compared the voltages with those given on the label on the rear of the panel. VS, VA, Vsc, Ve etc

At this point I can't offer any further advice since my knowledge of Plasma's is very limited other than what I read on this Forum.

[Biruslapio]

Re: Defective chip on ribbon cables

it's nearly impossible to replace a 'x' buffer chip,even if it's a 1366x768 plasma,which generally has 16 buffers,the math is > 1366/16x3=256 microscopic wires for each buffer,times 3 because red/green and blue pixels,if it's a full HD it's even worse,360 wires,it's just not possible the solder would just crack and short itself.
try unplugging each one and see which is interfering with the image,one failed buffer can mess up the output from all of them,remember to always put back the heatsink before powering on.

[Lloyd6202]

Re: Defective chip on ribbon cables

The bottom Ysus buffer is damaged and a replacment one should arrive monday..im glad that things should be ok at this point in time. Replaceing the whole ribbon is out of the question then so i will wait till monday when bottom buffer shows up and then post pics and see where things are

[Lloyd6202]

Re: Defective chip on ribbon cables

Yes i did measure and set to the values on the label except i did not let it warm up before i did that the board itself was tested and all was well but i will check again

[Biruslapio]

Re: Defective chip on ribbon cables

the 'x' board it's the usual name,ysus is what plug in the buffers that drive horizontal lines.
x boards have only 1 or 2 active components in them,SMD chips most of the time,the rest is just capacitors and resistors that don't fail under normal conditions,if swapping the board fixes the problem you are very lucky indeed.
There is a method to check the TCP,use a multimeter in diode mode at the pins in the middle of the connector,check them on a good one and one that you suspect it's causing the problem,should read 0.7~0.6V on some pins.

[Lloyd6202]

Re: Defective chip on ribbon cables

Still waiting on my board to get here

[Lloyd6202]

Re: Defective chip on ribbon cables

Tommorow it should be here the oliday and I ur border is always a delay

[Lloyd6202]

Re: Defective chip on ribbon cables

Ok here we go and this is what is whats happening now...a line thru the screen good news is that its not the ribbon cable i suspected could it be another or something else. Im kinda at a loss HELP

[Lloyd6202]

Re: Defective chip on ribbon cables

VA 55.2v
VS 203 v
Vsc 143v
Vy 193v
Vzb 90.1v